1. Field
The present disclosure relates to systems and techniques for originating calls in multi-mode network environments.
2. Background
The demand for wireless services has led to the development of an ever increasing number of wireless networks. One such network is a CDMA 1X (Code-Division Multiple Access) system which supports wireless voice and data services using spread-spectrum techniques. A competing network which has become the de facto standard in Europe and Asia is GSM (Global System for Mobile Communications). Unlike CDMA 1X, GSM uses narrowband TDMA (Time-Division Multiple Access) to support wireless voice and data services. Other networks that have evolved over the years include CDMA 1xEV-DO for high speed data services based on spread-spectrum technology, GPRS (General Packet Radio Service) which supports high speed data services with data rates suitable for e-mail and web browsing applications, and UMTS (Universal Mobile Telecommunications System) which can deliver broadband voice and data for audio and video applications.
In general, communications devices that are compatible with one wireless network are incompatible with other wireless networks. This is due, in part, to each network's use of its own unique protocols for communicating between compatible communications devices. In addition, each wireless network may have its own unique set of services. For example, CDMA 1X, GSM and UMTS support both wireless voice and data services whereas CDMA 1xEV-DO and GPRS are limited to wireless data services. Even wireless networks that support the same services may not be compatible with one another due to different operating parameters.
These disparate networks have created a series of islands of wireless service throughout the geographic landscape, each with its own unique set of protocols, services, and data rates. Accordingly, there is a need for a methodology wherein a user can communicate with different wireless networks in a simple and efficient manner. The specific methodology should provide an ability to originate a call on any one of the multiple networks.